Hand-held, low-flow therapeutic gas dispensers

ABSTRACT

A hand-held, low-flow dispenser comprises an enclosure holding a gas cartridge. A spring-biased needle is advanced to puncture a septum on the gas cartridge, and a separate spring-biased ball valve is used to turn the resulting gas flow off and on as well as to control the flow rate.

CROSS-REFERENCES TO RELATED APPLICATIONS

1. Field of the Invention

The present invention relates generally to medical apparatus andmethods. More particularly, the present invention relates to methods andhand-held apparatus for delivering therapeutic gases at a low-flow ratesuitable for patient administration.

Gas delivery systems for inhalation therapies are well-known. Drugs,mists, vapors, and the like, can and be delivered from a wide variety ofhand-held and other apparatus. For example, heated liquids have beenused to provide vapors for delivering a wide variety of drugs andtherapies. Hand-held devices have also been developed for both oral andnasal inhalation delivery. For example, powders may be delivered usingdisc inhalers where the patient inspires powder medicine from areceptacle on a disc. Metered-dose inhalers (MDI's) rely on apressurized propellant in a cartridge for delivering pressurized dosesof a drug to a patient. Most if not all of these drug delivery devicesare intended to provide a relatively high gas flow rate compatible witha patient's inhalation rate.

Recently, a new therapy relying on the non-inhalation administration oftherapeutic gases at relatively low-flow rates on the order of 0.5cc/sec to 20 cc/sec has been proposed. As described in U.S. Pat. No.7,017,573, carbon dioxide and a variety of other therapeutic gases aresuffused through a patient's nasal and/or oral cavities withoutinhalation. Typically, the gases are introduced from a dispenser to apatient's nostril and allowed to flow through the nasal cavity whileexiting through the other nostril or the mouth. The gases, such assubstantially pure carbon dioxide, can be irritating to the throat andlungs if inhaled, and flow rates higher than 10 cc/sec to 20 cc/sec canbe uncomfortable to the patient.

U.S. Pat. No. 7,017,573 describes a hand-held dispenser suitable fordelivering such low-flow rates, where the particular flow rate ispatient adjustable. The device relies penetrating a needle through aseptum on a cartridge of the carbon dioxide or other therapeutic gas.The flow rate is controlled by rotating a cap which holds the needle,where such rotation axially translates the needle in and out the holewhich was originally formed. The flow rate is thus controlled by theannular opening between the needle and the hole in the septum where thearea of the annular varies depending on the axial position of theneedle.

While this is a workable system, the dimensions of the needle and othersystem components must be carefully controlled in order to assure boththe ability to stop flow entirely as well as the ability to carefullyadjust the flow rate between the desired minimum and maximum ranges. Theneed to provide such close tolerances on system components complicatesthe manufacturing and raises the price of the hand-held dispenserconsiderably.

For these reasons, it would be desirable to provide improved hand-held,low-flow therapeutic gas dispensers which are both reliable andrelatively simple to operate. Such hand-held dispensers should allow forrelatively low manufacturing costs, be convenient for held-held patientuse, provide stable, low-flow rates on the order of a fraction of acc/sec while being adjustable to higher flow rates from 5 cc/sec to 20cc/sec or even higher. At least some of these objectives will be met bythe inventions described hereinbelow.

2. Description of the Background Art

A list of relevant U.S. Patent documents and foreign patent documents isprovide below. U.S. Pat. No. 7,017,573 has been discussed above.

Number Date U.S. PATENT DOCUMENTS Inventor 7,017,573 April 2006 Rasor etal. 6,001,332 December 1999 Garrett 5,993,428 November 1999 Hardge5,983,891 November 1999 Fukunaga 5,941,241 August 1999 Weinstein et al.5,938,590 August 1999 Elliott 5,908,870 June 1999 McLeod 5,839,433November 1998 Higenbottam 5,807,357 September 1998 Kang 5,570,683November 1996 Zapol 5,562,644 October 1996 McLeod 5,485,827 January 1996Zapol 5,431,155 July 1995 Marelli 5,262,180 November 1993 Orlando et al.4,934,359 June 1990 Blaine 4,554,916 November 1985 Watt 4,465,067 August1984 Koch et al. 4,273,124 June 1981 Zimmerman 4,188,946 February 1980Watson et al. 4,137,914 February 1979 Wetterlin 4,067,499 January 1978Cohen 3,974,830 August 1976 LaVerne 3,934,585 January 1976 Maurice3,870,072 Ma 1975 Lindmann 3,776,227 December 1973 Pitesky et al.3,513,843 May 1970 Exler 3,127,058 March 1964 Johnston 2,920,623 January1960 Holt 2,860,634 November 1958 Duncan et al. 2,651,303 September 1953Johnson et al. 1,449,047 March 1923 Johnson 1,288,850 December 1918Easly FOREIGN PATENT DOCUMENTS Country 247 873 March 1947 CH 837 158April 1952 DE 14 91 660 August 1969 DE 89 06 590 October 1989 DE 4319612December 1994 DE 19548652 October 1997 DE 0 768 094 April 1997 EP2656218 December 1989 FR 408 856 April 1934 GB WO 91 08793 June 1991WO/PCT WO 93 00951 January 1993 WO/PCT WO 99/29249 June 1999 WO/PCT WO00/51672 September 2000 WO/PCT WO 00/57851 October 2000 WO/PCT

BRIEF SUMMARY OF THE INVENTION

The present invention provides improved hand-held, low-flow therapeuticgas dispensers which are both economical to manufacture and easy to useby the patient. The dispenser utilizes a high pressure gas cartridge,and separate mechanisms are used for opening the gas cartridge and forcontrolling the flow rate of gas to the patient. The opening mechanismpenetrates a septum on the gas cartridge to form an opening having asufficient clearance with the penetrating mechanism so that flow throughthe penetration will not limit the rate of flow to the patient. Theseparate flow control mechanism allows the user to repeatably and stablyadjust flow at very low-flow rates, typically from rates of from 0.5cc/sec or lower to rates of from 5 cc/sec, 10 cc/sec, 15 cc/sec, 20cc/sec, or higher. Moreover, the flow control mechanism will allow theuser to provide a complete shut-off of the gas flow with minimum risk ofleakage and maintenance of high gas pressure over extended time periods.In the exemplary embodiments, the flow control valve will typically becalibrated to deliver gas in the range from 1 cc/sec to 50 cc/sec

In a first aspect of the present invention, a hand-held, low-flow gasdispenser comprises an enclosure having a gas outlet. The enclosure isadapted to receive a pressurized gas cartridge having a penetrableseptum. A pin having a tip for penetrating the septum is carried in apin carrier having an “advanced” configuration for penetrating the pinthrough septum to form a hole or other opening (including round andother shapes) in the septum and a “retracted” configuration forwithdrawing the pin from the hole to allow gas flow from the cartridge.

As the pin is intended to open the gas cylinder but not to control flowtherethrough, it is advantageous that the pin be prevented fromreentering the hole that is created after it is retracted. This can beaccomplished, for example, by mounting the pin on a “bistable” mechanismwhich carries the pin in both an advanced configuration or position anda retracted configuration or position. By mounting the bistable carrierso that it automatically switches from the advanced configuration to theretracted configuration after the pin has penetrated the septum, the pincan be withdrawn from the hole and maintained in the retractedconfiguration. As illustrated in the specific embodiments below, thebistable carrier will typically comprise a spring having both anadvanced and retracted stable configuration where the pin or springengages a stop or other mechanism to push the spring from the advancedto the retracted configuration as the pin carrier is advanced. A varietyof other mechanical elements or components could also be provided toeffect such advancement and retraction of the pin.

A flow control system is placed in series with pin and pin carrier toreceive and adjust the flow rate of therapeutic gas released from thepenetration in the septum of the gas cartridge. The flow control system,however, will form a separate component or assembly and will beseparately adjustable from the pin and pin carrier used to penetrate theseptum of the cartridge. The flow control system will typically includeat least one flow control valve which acts as a hybrid valve/regulator,as described in greater detail below in connection with the specificembodiments.

Usually, the pressured gas cartridge will form a non-removable componentof the hand-held gas dispenser. In other embodiments, however, the gascartridge may be removably received within the enclosure to allowremoval and replacement of the gas cartridge after gas has beendepleted.

The pin in the septum-penetrating structure will usually have a solidcore, allowing very small pin widths to be utilized, typically in therange from 0.5 mm to 2 mm, with a tip radius less than 0.1 mm. The useof such narrow width pins is advantageous since it reduces the forcenecessary to penetrate the septum. The pins will typically have circularcross-sections, but could have a variety of non-circular cross-sections,such as having a narrow, triangular tip. Additionally, although solidcore needles are preferred, hollow core needles could be used althoughthey are generally less preferable. Prior art designs have often usedhollow needles in order to both penetrate the septum and provide a flowpath for pressurized gas leaving the cartridge. The need to provide ahollow passage within the penetrating needle requires use of a largerneedle which can increase the necessary needle penetration force andrender manufacturer and use of the dispenser more difficult.

In the exemplary embodiments, the septum-penetrating pin is carried on aspring-loaded carrier, such as a spring disc, having a concave or otherretracted configuration and a convex or other advanced configuration. Asthe carrier and pin are advanced forwardly to penetrate the septum, theywill engage a stop or other structure surrounding the septum which willpush the carrier back to the retracted (concave) configuration after theseptum has been fully penetrated. In the concave configuration, thespring is abruptly withdrawn from the hole or other opening that it justcreated, thus creating a flow path around the pin from the cartridge andthrough the septum. This flow path will be relatively unobstructed asthe pin has been withdrawn to provide a large clearance area. The septumwill remain open (with the pin retracted) throughout the use of the gasdispenser until the cartridge is depleted. Turning the flow of gas onand off as well as regulating the flow rate will be accomplished usingthe flow control system which is a separate component of the gasdispenser.

In the exemplary embodiments, the flow control system will comprise aspring-loaded valve with an axial valve stem for pushing a ball or otherclosure element against the spring force. In its unloaded configuration,the valve element closes against a valve seat under the spring force andpressurized gas. When the valve element is pushed by the stem, anopening will be formed between the valve seat and the ball valve topermit a controlled flow of gas, where the flow rate is typically in theranges described above. As a particular advantage of the presentinvention, the gas pressure and spring force both tend to close the ballvalve against the valve seat, thus providing a fail-safe mechanism forshutting off the gas flow when it is desired to stop using thedispenser. The valve seat may be rigid or compliant. Rigid valve seatsmay be preferable as they provide more repeatable flow performance inresponse to temperature and other environmental changes.

In addition to controlling flow rate, the flow control system will alsoprovide for a pressure reduction where the small aspect ratio betweenthe ball or other closure element and the size of the piston (describedin more detail below) contribute greatly to the pressure reductioncharacteristics.

In the exemplary embodiments, the flow control valve is located in theenclosure between the gas cartridge and the outlet, typically having theseptum-opening pin therebetween. In alternate embodiments, the flowcontrol valve may be located in the neck of the gas cartridge. Havingthe control valve located in the gas cartridge would be particularlyadvantageous in embodiments where the gas cartridge is replaceable sothat a fresh flow control element is provided each time the cartridge isreplaced.

The hand-held, low-flow gas dispenser of the present invention isparticularly useful for delivering carbon dioxide and other therapeuticgases to a patient's nasal and/or oral cavities, typically in theabsence of inhalation, as described in U.S. Pat. No. 7,071,573, the fulldisclosure of which has been previously incorporated herein byreference. For such use, the gas outlet of the enclosure is typicallyadapted to seal against a nostril of the patient.

In a second aspect of the present invention, methods for dispensing alow-flow rate gas from a hand-held dispenser comprise pushing aspring-loaded pin through a septum on a gas cartridge in the dispenserto create a hole or other opening. The pin is allowed to spring back orotherwise retract from the opening to permit gas flow through aclearance surrounding the pin in the hole to an outlet on the dispenser,and a separate valve assembly is adjusted on the dispenser to controlthe flow rate of the gas. Typically, the gas will be a therapeutic gas,more typically being carbon dioxide. Carbon dioxide therapeutic gaseswill usually comprise at least 50% carbon dioxide by volume, often beingsubstantially pure carbon dioxide. The valve will be adjusted to controlflow at a desired rate, typically from 1 cc/sec to 50 cc/sec, moretypically from 0.5 cc/sec to 20 cc/sec Adjusting the flow usuallycomprises turning a nose piece or other dial on the enclosure whichadjusts the position of a spring-loaded ball valve, where the ball valveis usually located between the gas cartridge and the outlet within theenclosure. Although the flow control valve is typically adjusted using anose piece on the hand-held dispenser, it will be appreciated that othercontrol interfaces, such as sliding actuators, pushing actuators, otherrotating actuators, and the like, could be provided for adjusting theflow rate.

In a third aspect of the present invention, a low-flow rate gasdispenser is manufactured by providing an enclosure having an outlet, aseptum-penetrating pin, and a control valve stem. A gas cartridge isprovided having a penetrable septum and a spring-loaded valve. The gascartridge and the enclosure are assembled so that the pin is locatedadjacent the septum, and the control valve can engage the spring-loadedvalve after the septum has been penetrated. Optionally, the assembly maybe performed by a user who is replacing a spent cartridge with a newcartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a hand-held, low-flow gas dispenserconstructed in accordance with the principles of the present invention.

FIG. 2 illustrates a lower assembly of the gas dispenser with an uppercover removed.

FIG. 3 illustrates the lower assembly of FIG. 2 with an upper assemblyremoved.

FIG. 4 is an exploded view of the system components of the upper andlower assemblies of FIGS. 2 and 3.

FIG. 5 is an exploded view, in cross-section, of the upper assembly.

FIG. 6 is cross-sectional view of the lower assembly.

FIGS. 7A-7C illustrate the steps of puncturing a septum of a gascartridge and thereafter controlling flow rate using a ball valveassembly.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in FIGS. 1-3, a hand-held, low-flow gas dispenser 10constructed in accordance with the principles of the present inventioncomprises a lower assembly 14 and a cover 12. Removing the cover 12reveals an upper assembly 16 (FIG. 2) including a nose piece 18 having afitted end 20 which releases the therapeutic gas. Typically, the fittedend 20 is adapted to conform to a patient's nostrils for nasal infusion.It will be appreciated, however, that the shape could be modified fororal infusion or for conformance to other body orifices where deliveryof a therapeutic gas might be desired.

Referring now to FIGS. 4 and 6, the lower assembly 14 comprises ahousing or shell 22 which receives a gas cartridge 24 having apenetrable septum 26 at its upper end. The cartridge 24 has a threadedneck 28 and is held within the shell 22 by a cylinder nut 30 which sealsto an upper lip 32 of the enclosure, as best seen in FIG. 6. Althoughshown with a threaded engagement, the cylinder could also have anon-threaded neck which is held by other mechanisms within thedispenser. A cylinder gasket 34 seals the septum to a passage 36 in athreaded neck 38 of the cylinder nut 30. Thus, it will be appreciatedthat if the septum 26 in the cylinder 24 is penetrated, gas will be ableto flow upwardly through the passage 36. The gasket 34 provides a firstmode of over pressure relief. When the flow control valve is closed, thegasket 34 will be exposed to pressure from the gas cylinder after thegas cylinder has been opened. If the pressure in the gas cylinderexceeds the expected value for any reason, such as exposure to heat, thematerial or other characteristic gasket 34 may be selected so that itwill extrude in response to the pressure in order to permit release ofthe excess pressure through the side of the hand-held enclosure.

Referring now to FIGS. 4 and 5, the upper assembly 16 comprises aregulator body 40, the nose piece 18, a nose piece nut 42, and a needle44 carried in a carrier formed as a disc spring 46. The regulator body40 carries a valve seat insert 48 (the seat could alternatively beformed integrally with the regulator body 48) sealed by an O-ring 47, asbest seen in FIG. 5, which comprises a ball 50 biased upwardly by spring52 held in place by a filter 54 at its lower end. The spring 52 biasesthe ball upwardly against a cylindrical seat 56 formed at the lower endof a passage 58. As will be described in more detail below, a valve stem60 is used to axially depress the ball 50 in order to open an annular orother passage between the ball and the seat 56. Gas flowing up throughthe passage 36 from cartridge 24 will pass through the filter 54, pastthe ball 50, through the passage 58, and into the nose piece 18. Thus,the gas will ultimately pass out through the port in fitted end 20. Asecond mode of over-pressure relief is provided by forming the regulatorbody 40 to include a “failure weld” in a wall thereof. The failure weldwill be a slightly weakened portion which will fail in response toover-pressure from the gas cylinder when the regulator valve assembly isclosed.

The nose piece 18 carries a regulator piston 62 having the valve stem 60depending from its lower end. The regulator piston 62 is adapted totravel up and down in a receptacle 64 formed in the upper end of theregulator body 40. The regulator piston 62 has wings, bosses, or otherfeatures which travel in slots 68 surrounding the receptacle 64. Theregulator piston 62 is biased downwardly by a spring 70 and sealsagainst the inside of the receptacle 64 with 0-ring 66. A lower cam 72rides against an upper cam 74 formed in the inside of the nose piece 18so that rotation of the nose piece 18 relative to the remainder of thelower assembly 14 will cause the regulator piston to axially translateupwardly and downwardly, depending on the direction of rotation. In thisway, the valve stem 60 can be caused to lower against the ball 50 of theregulator valve assembly to allow the user to rotate the nose piece toboth turn on and off the flow as well as to regulate the flow to adesired rate, generally within the ranges set forth above. Additionalover-pressure failure modes may be provided in the nose piece in orderto prevent gas to flow through the fitted end 20 when exposed to excesspressure. For example, the O-ring 66 may be selected to have propertieswhich will fail in response to pressure above a pre-determinedthreshold. Alternatively, the O-ring 43 (FIGS. 4 and 5) disposed overnosepiece nut 42 could be selected to have properties which fail inresponse to such over-pressure.

Referring now to FIGS. 7A-7C, operation of the hand-held dispenser ofthe present invention will be described in greater detail. Initially, asshown in FIG. 7A, the needle 44 is held in the disc spring 46 with thedisc spring in an advanced (convex) configuration (i.e., flipped so thatthe needle is held in a relatively advanced configuration relative tothe septum 26). As the upper assembly 16 is rotated, a threaded lowerend 41 of the regulator body 40 will translate downwardly on thethreaded neck 28 of the lower assembly 14. This causes the needle 44 tomove downwardly and to penetrate into the septum 26, as shown in FIG.7B. Simultaneously, the disc spring 46 will engage the upper surface ofthe threaded neck 38, causing the disc spring to invert to assume aretracted (concave) configuration, as shown in FIG. 7B. This causes theneedle, which has penetrated the septum, to move upwardly from theseptum to leave an annular flow orifice 76 surrounding the needle 44,allowing gas to flow from the cartridge 24 upwardly.

Flow from the cartridge, however, will continue to be blocked by ballvalve 50 so long as it remains seated in seat 56, as shown in FIG. 7B.To open the valve and allow flow, the nose piece 18 is rotated to causecams 72 and 74 to lower the regulator piston 62 to cause the valve stem60 to push the ball valve 52 downward, as shown in FIG. 7C. At thispoint, an open flow path through the port and fitted end 20 is created,and gas will flow upwardly as shown by the arrows in FIG. 7C. The rateof gas flow can be finely adjusted by the user by rotating the nosepiece 18. The flow may be shut off entirely by fully rotating the nosepiece so that the valve stem 60 allows spring 52 to push the ball 50back against seat 56, again as shown in FIG. 7B.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention which is defined by the appendedclaims.

1. A hand-held, low-flow gas dispenser comprising: an enclosure having agas outlet; a pressurized gas cartridge having a penetrable septumwithin the enclosure; a pin having a tip for penetrating the septum; apin carrier adapted to advance the pin through the septum to form a holeand to retract the pin from the hole to allow gas flow from thecartridge, wherein the pin is prevented from reentering the hole; and aflow control valve in series with but separate from the pin and pincarrier for selectively controlling the flow rate of gas released fromthe cartridge.
 2. A dispenser as in claim 1, wherein the pin carriercomprises a bistable mechanism which is shifted from an advancedconfiguration to a retracted configuration after the carrier advances apredetermined distance.
 3. A dispenser as in claim 2, wherein thebistable mechanism comprises a spring.
 4. A dispenser as in claim 1,wherein the pressurized gas cartridge is removably disposed in theenclosure.
 5. A dispenser as in claim 1, wherein the pressurized gascartridge is non-removably disposed in the enclosure.
 6. A dispenser asin claim 1, wherein the pin has a solid core.
 7. A dispenser as in claim6, wherein the pin has a width in the range from 0.5 mm to 2 mm.
 8. Adispenser as in claim 1, wherein the pin carrier comprises a bistablespring having an advanced configuration and a retractable configuration.9. A dispenser as in claim 1, wherein the flow control valve comprises aspring-loaded ball valve with a rotatable stem for opening the valveagainst the spring.
 10. A dispenser as in claim 9, wherein the flowcontrol valve is calibrated to deliver gas at a flow rate in the rangefrom 1 cc/sec to 50 cc/sec
 11. A dispenser as in claim 9, wherein theflow control valve is located in the enclosure between the gas cartridgeand the outlet.
 12. A dispenser as in claim 9, wherein the flow controlvalve is located in a neck of the gas cartridge.
 13. A dispenser as inclaim 1, wherein the outlet is adapted to seal against a nostril.
 14. Adispenser as in claim 1, further comprising means for redirecting awayfrom the gas outlet gas flow in the event of overpressure of the gascartridge.
 15. A dispenser as in claim 14, wherein the means comprises afailure weld in a component exposed to pressure from the gas cartridgewhen the flow control valve is closed.
 16. A dispenser as in claim 14,comprising a gasket between the gas cylinder and the enclosure, whereinthe gasket extrudes in response to overpressure when the flow controlvalve is closed.
 17. A dispenser as in claim 14, comprising an O-ringabove the flow control valve which fails in response to overpressurewhen the flow control valve is open.
 18. A method for dispensinglow-flow rate gas from a hand-held dispenser, said method comprising:penetrating a pin through a septum on a gas cartridge in the dispenserto create a hole; retracting the pin from the hole to permit gas flowthrough the hole to an outlet on the dispenser, wherein the pin isprevented from reentering the hole; and adjusting a separate valve onthe dispenser to control the flow rate of the gas through an outlet onthe dispenser.
 19. A method as in claim 18, wherein the pin is mountedon a pin carrier which shifts from an advanced configuration to aretracted configuration as the pin or carrier engages a stop in thedispenser.
 20. A method as in claim 19, wherein the carrier comprises abistable spring which springs from the advanced to retractedconfigurations.
 21. A method as in claim 18, wherein the gas is atherapeutic gas.
 22. A method as in claim 21, wherein the therapeuticgas comprises carbon dioxide.
 23. A method as in claim 22, wherein thegas comprises at least 50% carbon dioxide by volume.
 24. A method as inclaim 18, wherein the valve is adjusted to control flow at a rate from 1cc/sec to 50 cc/sec
 25. A method as in claim 18, wherein adjustingcomprises a rotating nose piece which adjusts the position of aspring-loaded ball valve.
 26. A method as in claim 18, wherein thespring-loaded ball valve is disposed between the gas cartridge and theoutlet.
 27. A method as in claim 18, wherein the spring-loaded ballvalve is disposed in the cartridge.
 28. A method as in claim 18, furthercomprising redirecting gas flow away from the gas outlet in the event ofoverpressure of the gas cartridge.
 29. A method as in claim 28, whereinredirecting comprises at least one of ring failure, gasket failure, andcomponent weld failure.
 30. A method for manufacturing a low-flow rategas dispenser, said method comprising: providing an enclosure having anoutlet, a septum-penetrating pin, and a control valve stem; providing agas cartridge having a penetrable septum and a spring-loaded valve; andassembling the gas cartridge and the enclosure so that the pin islocated adjacent the septum and the control valve stem can engage thespring-loaded valve after the septum has been penetrated.